The mills were of various types.  One of the largest was called the Elephant.  It had two huge (some 12 feet in diameter) cast iron wheels connected with an axle and which would rotate about a central shaft, looking not unlike the narrowly-spaced front tires of some farm tractors.  Beneath the cast iron wheels was a large plate of iron, or “bed plate”.  The three ingredients of black powder were placed upon the iron plate and moistened with a little water (to prevent sparking).  Then, the large wheels were placed in motion and the ingredients were ground together into a homogenous mixture...similar to mixing sugar and flour in order to make cake and cookies.  None of the men were in the building when the wheels were started.  There was always danger of an explosion.  Remember, black powder is intended to explode...that is how it does its useful work. You may wonder how the mills were started if none of the men were inside.  The answer is that they were started from another building some distance from the mill.  One such building still stands today.  It is very small and has very thick concrete walls, offering protection from the man or men who started the mill. 

After a thorough grinding, the big wheels were stopped and the powder was taken out using wooden shovels.  Shovels made of wood would not spark and, therefore, would not start an explosion.  Next, the powder was moved to a “Corning” mill, where it was formed into small pellets of different sizes.  Depending on the application for the black powder, the size is important as it controls the rate of burning.  Powder for firearms, like the muzzle-loaders still in use today, is fairly fine in texture.  Powder used for blasting rock in the mines and in quarries is somewhat coarse, and burns slower.  Modern gunpowders, made of nitrocellulose, still maintain control over the size of the grains for the same reasons.

After the powder was formed into grains, it was moved to the “Can House”, where it was packed into metal or wooden containers.  Then the powder was moved to a building called the “Magazine”, which was far away from any other buildings.  There it was stored until time for shipment to the mines or other destination.  A small railroad ran the length of the mill property and on down to the Susquehanna River.